In the 1930s, jazz was a very different animal from the music we hear today when we put on a John Coltrane or Wynton Marsalis album. Back then, jazz was pop music, which meant you danced to it. Like today’s jazz, it definitely swung but it also had a strong four-on-the-floor pulse, a kind of Depression-era version of the modern dance club.
Swing-era drummers laid down that pulse using large bass drums (24"–28") that hearkened back to the days of marching bands. They also used a small, thin hi-hat, which was only about 11"–12" in diameter. The concept of a ride cymbal did not yet exist.
In the mid 1940s, a new sound evolved from swing called bebop. Bebop, or bop, grew out of a desire by African-American musicians to create music that was no longer specifically tied to dancing, but rather something that functioned as a unique expression of the black experience. Bebop included complex melodic lines, expressive solos, and more interaction between the musicians. The music took jazz in a more artistic direction and established the “straight-ahead” blueprint we still follow today.
So how did bebop drumming pioneers like Max Roach and Kenny Clarke change what they were doing to fit into this conversation? First, they sized their bass drums all the way down to 18"–20", treating them more like toms than thuddy timekeepers. Second, they went to the cymbal manufacturers and demanded bigger, heavier mounted cymbals on which they could “ride” the time in a way that was lighter and more expressive than the hi-hat.
With this new setup, a bebop drummer could float over the rest of the band with his time feel, using the bass and snare drums to comment on what other band members were playing.